Long radius template, carriage and scribing scale



July 23, 1968. R. F. S-TONEIMAN LONG RADIUS TEMPLATE, CARRIAGE AND SCRIBING SCALE Filed July 18, 1967 3 Sheets-Sheet 1 INVENTOR F/cHA/PD 570 IVEMA 1v July 23, 1968 RFSTOgEMAN 3,393,453

LONG RADIUS TEMPLATE, CARRIAGE AND SCRIBING SCALE 5 Sheets-Sheet 2 Filed July 18, 1967 INVENTOR /P/cHA/P0 sro/vem/vv 75-4.- Avg ATTORNEY July 23, 1968 STONEMAN Q 3,393,453

LONG RADIUS TEMPLATE, CARRIAGE AND SCRIBING SCALE Filed July 18, 1967 s Shets-Sheet 5 INVENTOR /?/cHA/P0 1 STONEMAN 6a ATTORNEY United States Patent 3,393,453 LONG RADIUS TEMPLATE, CARRIAGE AND SCRIBING SCALE Richard F. Stoneman, 7622 Holly Drive, Mentor-Lake, Ohio 44060 Filed July 18, 1967, Ser. No. 654,176 9 Claims. (Cl. 33-27) ABSTRACT OF THE DISCLOSURE An instrument for scribing circles having long radii, without using the point of origin of a radius as a center, and which includes a carriage which travels in selected arcuate grooves or channels of a template and onwhich is mounted a head which slidably supports a graduated radius arm which carries a scriber.

Background or the invention This invention relates to the art of drawing instruments adapted for use by draftsmen, engineers, architects, and the like.

The prior art discloses instruments of the parallelogram-type for scribing arcs or large circles, but which are of much more complicated construction than the present invention. The prior art also discloses instruments for scribing ovals, ellipses and circles utilizing a grooved template and a pin for engaging in the groove thereof and which is carried by an adjustable radius arm.

Summary It is a primary object of the present invention to provide an instrument which is capable of use for most accurately scribing arcs of circles without the necessity of utilizing the points of origin of the radii of said arcs or circles as a center.

Another object of the invention is to provide an instrument capable of use in scribing arcs having radii covering a wide range of different lengths and in increments varying as little as one-sixteenth of an inch.

A further object of the invention is to provide an instrument including means by which the instrument can be accurately relocated for continuing the arc of a circle beyond an extreme limit of travel of the scriber; and which means additionally functions to facilitate accurately scribing a radius or a tangent line at any point along the arc.

Still another object of the invention is to provide a novel template and a novel carriage for operation in selected arcuate channels of the template for insuring accurate movement of a scriber in an arc concentric to the channel engaged by said carriage.

Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings illustrating a preferred embodiment thereof, and wherein:

Brief description of the drawings FIGURE 1 is a top plan view of the scribing instrument;

FIGURE 2 is an enlarged fragmentary sectional view taken substantially along the line 2-2 of FIGURE 1;

FIGURE 3 is a fragmentary cross sectional view taken substantially along the line 3-3 of FIGURE 2',

FIGURE 4 is a fragmentary horizontal sectional view taken substantially along the line 4-4 of FIGURE 3;

FIGURE 5 is a horizontal sectional view of the lower portion of the carriage taken substantially along the line 5-5 of FIGURE 3;

FIGURE 6 is an enlarged cross sectional view of a part Ice of the lower portion of the carriage taken substantially along a plane as indicated by the line 6-6 of FIGURE 5;

FIGURE 7 is an enlarged fragmentary transverse sectional view taken substantially along the line 7-7 of FIGURE 3;

FIGURE 8 is an enlarged fragmentary vertical sectional view taken substantially along the line 8-8 of FIG- URE 1;

FIGURE 9 is a cross sectional view of the template and base, on an enlarged scale relative to FIGURE 1;

FIGURE 10 is a side elevational view of the radius arm;

FIGURE 11 is an enlarged fragmentary horizontal sectional view taken substantially along the line 11-11 of FIGURE 8;

FIGURE 12 is a fragmentary bottom plan view of a part of the carriage frame;

FIGURE 13 is a plan view of a mobile supporting element of the carriage frame, and

FIGURE 14 is a fragmentary side elevational view of a tangent line marking device to replace the radius line marker of FIGURE 8.

Description of the preferred embodiment Referring more specifically to the drawings, the scribing instrument in its entirety and comprising the invention is designated generally 17 and includes an elongated template 18 having a fiat under side 19 which is disposed on and secured to the upper side of a flat base plate 20 having the same marginal shape or configuration as the template 18. The template 18 has three arcuate channels 21, 22 and 23 adjacent its inner front edge 24 and which extend substantially from end-to-end thereof. As seen in FIGURE 9, the channels 21, 22 and 23 extend completely through the template, so that portions of the upper side of the base plate 20 constitute the bottoms of said channels. The radii of said channels is designated by the indicia 25 (FIG URE l) which indicia may be in inches, degrees or other suitable scales. The other rear portion of the template 18 has a depression 26, extending preferably nearly to the ends thereof, for a purpose which will hereinafter be described. The template .18 may be formed of plastic, aluminum, or other substantially rigid light material. The concentric concave and convex side walls of each of the channels 21, 22 and 23 provide hard, smooth surfaces to offer a minimum of frictional resistance to the travel of a carriage 27 in the channels as will hereinafter be described. The upper surface of the base plate 20 provides a hard smooth surface for the mobile support of the carriage 27 which rides thereon, and said base plate functions to reinforce the template.

The carriage which is constructed to travel in any one of the channels 21, 22 and 23 includes an elongated rigid frame 28 including a bottom wall 29, corresponding end walls 30, and a top wall 31. The frame is preferably formed of a heavy material such as chrome plated steel or nickel plated brass. The top wall 31 is detachably secured on the end walls by screws 32 which engage in upwardly opening threaded sockets 33 of said end walls, as seen in FIGURE 4.

As best seen in FIGURE 5, the bottom 29 is provided with two circular upwardly opening sockets 34 which are disposed adjacent the end walls 30 and near the concavely bowed back side 35 of the frame 28; and two elongated upwardly opening sockets 36 which are disposed crosswise of the frame 28, between the sockets 34 and nearer to the other front side 37 of the frame. The top wall 31 is also provided with downwardly opening sockets 34 and 36' which align with and correspond to the sockets 34 and 36, respectively. Bearings 38 are contained in and protrude from the sockets 34 and 34 and provide journals for spindles 39 which project axially from the upper and lower ends of rollers 40 which are thus rotatably mounted between said bearings. Bearings 41 are mounted in and protrude from the sockets 36 and 36 to provide journals for spindles 42 which roject axially from the upper and lower ends of rollers 43 which are thus rotatably mounted between said bearings 41. As seen in FIGURE 5, the bearings 41 are slidably movable in the sockets 36 and 36' in directions crosswise of the frame 28. A split pin 44 projects upwardly from the bottom 29. The intermediate portion of a leaf spring 45 is secured in the slot of the pin 44 and the end portions of said spring bear against the bearings 41 of the sockets 36 for urging said bearings and the rollers 43 toward the convex side 37 of the frame 28. The top wall 31 has a corresponding pin 44 and leaf spring 45 on its under side and which similarly functions with the bearings 41 of the sockets 36'. As seen in FIGURE 4, the rollers 40 are of larger diameter than the rollers 43.

A flat under side 46 of the bottom 29 has recessed end portions 47. Said recessed end portions 47, as best seen in FIGURES 7 and 12, are each provided with a downwardly opening hemispherical cavity 48, and two aligned grooves 49 of semi-circular cross section which open into the cavity 48 and are disposed crosswise of the bottom 29, to accommodate a portion of a spherical roller 50 and portions of two aligned stems 51, which project from the roller 50, respectively. As seen in FIG- URE 7, a plate 52 is secured against each recessed end 47 by screw fastenings 53, and has an opening 54 through which a portion of the roller 50 protrudes, and aligned grooves 55, of semi-circular cross section, in which portions the spindles 51 are journaled. The under sides of the plates 52 are disposed flush with the bottom surface 46. The carriage 28 may be mounted for movement in any one of the channels 21, 22 and 23 with the rollers 50 resting on the base plate 20 to provide a mobile support for the carriage in the template channel, and with the rollers 40 bearing against the inner convex wall 56 of said channel and the rollers 43 hearing against the outer, concave channel wall 57.

The top wall 31 has a pair of spaced upstanding apertured cars 58. An elongated radius arm supporting head 59 has a bottom wall 60 which is provided, intermediate of its ends, with transversely aligned depending apertured ears 61 which fit between the cars 58. A pivot pin 62 extends through the ears 58 and 61 for pivotally mounting the head 59 on the carriage 27 about an axis disposed substantially longitudinally of said carriage and crosswise of the head. The head 59 which is preferably formed of a lightweight but rigid transparent plastic material has a bore 63 extending from end-to-end therethrough, as seen in FIGURE 3, which is of a height greater than its width, to slidably receive therein an elongated radius arm 64 which is likewise preferably formed of a lightweight rigid plastic material and which is of beam-shaped cross section to increase the rigidity thereof. The head 59 has a longitudinally extending cavity 65 in its upper part which opens downwardly into the bore 63 to receive a leaf spring 66 the ends of which yieldably bear upon the upper edge of the arm 64 and the intermediate portion of which is Secured to the top of the cavity 65, intermediate of its ends. The spring 66 prevents accidental or casual slippage of the arm 64 relative to the head 59.

A scriber holder 67, as best seen in FIGURE 8, has a shank 68 of square cross section, one side of which abuts against the outer end of the radius arm 64 and is secured thereto by screw fastenings 69 to mount the holder 67 in a vertical position. The holder 69 has a conventional chuck 70 at its lower end for supporting a conventional scribing element 71 which may be either an ink or lead scriber. The holder 67 has a post 72 at its upper end of square cross section, and which is disposed above the radius arm 64, to receive either a cap 4 73 (FIGURES 8 and 11) or a cap 74 (FIGURE 14). Each cap fits slidably but non-rotatably on the post 72.

The cap 73 has a boss 75 projecting from one side thereof in which is secured one end of a right angular rod 76 which extends outwardly therefrom and then downwardly. The rod 76 is disposed with its depending portion intersecting an extension of the longitudinal axis of the radius arm 64 and terminates in a point 77 at its lower end. The rod 76 constitutes a radius marker as will hereinafter be described.

The cap 74 has bosses 78 projecting from opposite sides thereof for receiving two rods 79, corresponding to the rod 76, which terminate in points 80. The cap 74 is applied so that the rods 79 are disposed crosswise of the arm 64 to function as tangent markers, as will hereinafter be described.

As best seen in FIGURE 10, both sides of the radius arm 64 are graduated in inches, as seen at 81, with the 0 graduations spaced from the outer end of the arm. Other types of linear scales may be substituted for the scales 81 as shown. As seen in FIGURE 2, the side walls of the head 59 are provided with hair lines 82 for use with the scales 81 for accurately setting the radius arm relative to the head. The spacing of the 0 graduations from the outer end of the arm permits said graduations to register with the hair lines 82 when the carriage 28 is positioned in the innermost channel 23.

The bottom wall 60 of the head 59 has a bore 83 extending longitudinally therethrough to receive a second radial marker 84 the horizontal portion of which fits slidably in said bore and the depending vertical portion of which is disposed between the template 18 and scriber 71. The radial marker 84 is mounted slidably in the head 59 for use when the carriage 28 is in any one of the channels of the template.

A stop 85 extends downwardly from the forward part of the bottom wall 60 and clears the upper surface of the template 18 by approximately one-sixteenth of an inch when the axis of the head 59 and arm 64 is in a horizontal plane. The stop 85 will engage the top surface of the template 18 if the scriber 71 wears down, to prevent the inscribing of an inaccurate arc.

The base plate 20 may be positioned on any smooth horizontal supporting surface 86. The carriage 28 is positioned in the desired channel and the radius arm 64 is adjusted in the head 59, utilizing one of the scales 81 and one of the hair lines 82, for locating the scriber element 71 at a point representing a radius of a desired length. The bore 63 prevents any lateral or rocking movement of the arm 64 relative to the head 59 and the spring 66 retains the arm in its correctly adjusted position relative to the head 59. With the carriage disposed at one end of the selected channel, said carriage is manually propelled in the template toward the other end of the channel so that an are having a desired radius will be inscribed by the scriber element 71 on the surface 86. The large rollers 48 by bearing against the convex inner wall 56 of the channel will retain the scriber element 71 in a correct position for scribing the desired arc, and the smaller spring pressed rollers 43 by engagement with the concave wall 57 retain the large rollers 40 in correct rolling engagement with the wall 56.

The pointed lower ends of the radially aligned radial markers 76 and 84 are disposed slightly above the surface 86, as are the pointed ends of the tangent markers 79, when substituted for the radial marker 76. A pencil mark may be made beneath the pointed lower ends of the radial markers 76 and 84, at any point in the travel of the carriage 28 so that a radius line may be accurately scribed through said pencil marks. The tangent markers 79 may be similarly utilized for marking two points between which a line can be drawn for accurately applying a tangent line to any portion of the are being inscribed. In addition, either set of said markers may be employed for locating reference points when the carriage 28 has traveled the length of a channel so that the template can be reset on the surface 86 with the carriage at the other end of the channel and with the two markers again located directly over the two reference points.

The hand of the operator, not used for propelling the carriage 28, may be placed in the depression 26 of the template, with the arm of said hand resting on the surface 86, for holding the template immovable during the scribing operation.

It will be apparent that templates having channels of different curvatures may be employed. With a total of eight templates each having three channels, it is possible to scribe arcs throughout a range of twenty-four inches to three hundred and twelve inches in increments of onesixteenth of an inch.

Various modifications and changes are contemplated and may be resorted to without departing from the function or scope of the invention, as hereinafter defined by the appended claims.

I claim as my invention:

1. An instrument for scribing long radius arcs comprising a template provided with a plurality of arcuate channels which are eccentrically disposed relative to one another, a carriage mounted for travel in any one of said channels, a head supported by said carriage above the template, a radius arm slidably supported by said head radially of said selected channel for adjustment in said head in directions axially of the arm, scribing means supported by and depending from an outer end of said radius arm for scribing an arc having a desired radius when said carriage is caused to travel in said selected channel, and a flat base plate secured to the underside of the template and adapted to rest on a supporting surface for supporting the scribing instrument, said base plate having flat smooth top portions forming the beds of said channels and on which the carriage rides.

2. A scribing instrument as in claim 1, said carriage including a frame, means depending from said frame and providing a mobile support for the carriage in said selected channel, a pair of rollers journaled in said frame adjacent the ends thereof and about vertical axes, said rollers protruding from the frame and bearing against the convex side wall of the selected channel, a second pair of rollers journaled in said frame about vertical axes and disposed between said first mentioned pair of rollers, spring means yieldably urging said second pair of rollers against the other concave side Wall of said channel for yieldably retaining the first mentioned pair of rollers against said convex channel wall.

3. A scribing instrument as in claim 1, said head and radius arm being formed of lightweight material as compared to said carriage.

4. A scribing instrument as in claim 1, means pivotally mounting said head on said carriage about an axis disposed crosswise of the axis of the radius arm, and means limiting rocking movement of the head and radius arm in one direction relative to the carriage and template to prevent the scribing means from contacting a surface on which the template is supported when said arm and head are not disposed substantially parallel to said surface to prevent the scribing of inaccurate arcs.

5. A scribing instrument as in claim 1, means carried by said scribing means and by the head for accurately locating reference points at any position along an are being inscribed by said scribing means to facilitate the scribing of a line between said reference points and which is radial to the arc.

6. A scribing instrument as in claim 4, means carried by said scribing means to facilitate the accurate scribing of a line tangent to any point on the arc being inscribed by the scribing means.

7. A scribing instrument as in claim 1, said head having a bore extending longitudinally therethrough and in which said radius arm is mounted for sliding movement in directions only axially of the arm, said radius arm having a linear scale on at least one side thereof, and said head having a hair line for use as a reference point in conjunction with said scale.

8. A scribing instrument as in claim 7, and means carried by said head and bearing against said radius arm for resisting sliding movement of the radius arm in the head.

9. A scribing instrument as in claim 1, said channels being formed in a forward portion of the template, and said template having a recess in the upper side of its rear portion providing a hand rest.

References Cited FOREIGN PATENTS HARRY N. HAROIAN, Primary Examiner. 

